NEW YORK – This season’s clothes aren’t taking their cues from club kids, college students or teenage rebels. There’s something grown-up about some of the most popular looks: They’re a little refined and very wearable, but they’ve avoided being stodgy or, worse, just plain old.

Some of the influence could be coming from pop culture with “The Great Gatsby” and “Anna Karenina” among the most-anticipated movies before year’s end, and the popularity of TV period pieces such as “Downton Abbey,” “Mad Men” and “Boardwalk Empire.” No flannel PJ bottoms or ripped jeans there.

On fall-winter runways, Marlene Dietrich look-alikes appeared at Donna Karan, Charles Dickens-inspired characters at Marc Jacobs and the models at Louis Vuitton seemed poised for a romantic rendezvous on the Orient Express.

Polished sophistication can be tempting after going periods over the past decade that have alternately favored bohemian, aggressive and blingy looks.

“I’m not a psychologist, I’m just a fashion designer,” says Banana Republic creative director Simon Kneen, “but the air of fashion is a little more elegant right now. … We’re not in a moment when casual feels like the right mood.”

Some of the trends on retail racks include rich jewel tones of purple, blue and green, lace handiwork and refined accessories including brooches, opera gloves and top-handle bags.

The newness is coming from the feeling of aristocracy with a dash of opulence, says Brooke Jaffe, director of fashion accessories at Bloomingdale’s.

“Dressing from the top of society is where trends are coming from, not street trends. We started our fall trend report with the jewelry category, specifically ‘fantasy jewelry.’ Where’s that coming from? The royal family? ‘Downton Abbey’? I’m not sure, but we believe 120 million percent in fancy and opulent jewelry,” she says.

Buttery, work-appropriate leather pants, equestrian jackets, quilting and gilded baroque embellishments are also on the sophisticated shopping list, says Brandon Holley, editor-in-chief of Lucky magazine.

It’s not just fashion experiencing this adult-quake, says Tom Morton, North American chief strategy officer for forecasting and advertising company Havas Worldwide. He prepared a report that dealt with the “pushback against youth obsession.”

“People are going where the money is,” Morton says. A side effect of the economic downturn is that teenagers and 20-somethings aren’t entering the economy as early as their counterparts did a generation ago, he explains.

Meanwhile, famous faces aren’t leaving the stage as they age: Morton points to the popularity of Paul McCartney at the Olympics and Bruce Springsteen on the presidential campaign trail. Even James Bond is 50 – and actor Daniel Craig, who currently plays him, is 44.

Just passing a newsstand in Manhattan, Morton noted the celebrities on the covers of the glossy magazines – Jessica Alba, Eva Longoria and David Beckham, all in their 30s, and “everyone else was even older.”

And saying something is “modern” or “contemporary” is no longer shorthand for “young.”

“You look at the Apple store. It’s what contemporary life looks like, but there’s not an upper age limit on it. ... There was an assumption of people growing out of things, but that’s not happening,” Morton says.

Adam Glassman, creative director of O, The Oprah Magazine, says more people are comfortable in their own skin. Women aren’t necessarily using fashion and beauty as a tool to look younger, he observes. Instead, they’re using those tools to be the best 40-, 50- or 60-year-old they can be.

“When young people wear it, they looked pulled together, polished. When older women wear it – and, yes, they do have to be careful about going too far this way or they risk looking a bit like a dowager – they like the trends of being more covered, the return to hosiery and vintage jewelry. A lot of women appreciate sleeves on dresses,” he says.

Younger women are learning that sophistication doesn’t mean matronly, and they’re seeing these grown-up styles as a fast track to confidence and credibility, Glassman says.

One might think the plugged-in culture that allows one to run a business from a local coffee shop is an excuse to dress down, but it’s not, Kneen says. “You’re never doing just one thing. You have to prepare yourself for the unexpected: What meeting you’ll be called into unexpectedly, who you’ll bump into, if you’ll have coffee with a friend or go from there to dinner.”

He adds: “It’s just easier to be a little dressed up.”

Knowing you look the part of a responsible, respectable adult can make you stand a little straighter, says Jacqueline Durran, the costume designer of “Anna Karenina.” She worked with Kneen on looks inspired by the film to be sold at Banana Republic during the holiday season.

“As I see with my working in costuming, the act of simply putting on a piece of clothing can truly transform someone’s attitude and make them carry themselves in a different way,” Durran says. “This obviously translates beyond acting to everyday dressing, which is about feeling confident in what you’re wearing and looking poised in all situations.”